Conventionally, as for an information reception, recording and reproduction apparatus for implementing a time shift reproduction by utilizing a disk recording medium which allows random access, a method and an apparatus such as is described in Japanese unexamined patent publication H7(1995)-30851 which records TV programs in real time and reproduces at an arbitrary time are known.
In the following, a configuration and an operation of an information reception, recording and reproduction apparatus according to a prior art is described in reference to FIG. 32.
As shown in the figure, an information reception, recording and reproduction apparatus according to a prior art is formed of a time shift means 3200 for temporarily recording an analog input video signal such as a TV broadcast which is then reproduced, a switching part 3208 for receiving inputs of a video signal which is outputted from the time shift means 3200 and a video signal transmitted in real time so that one of the video signals is selectively outputted and a display part 3209 for displaying the video signal outputted from the switching part 3208.
Next, in the time shift means 3200, processing of the inputted video signal is as follows. That is to say, an AD conversion part (in the figure referred to ADC) 3201 digitally converts a video signal and a compression processing part 3203 compresses the digitally converted data and recorded it in a recording apparatus 3204 that is a recording medium allowing a random access. Here, it is possible to read out the video data recorded in the recording apparatus 3204 at an arbitrary time.
The video data recorded in the recording apparatus 3204 is outputted to an expansion processing part 3205 at a predetermined time which can be arbitrarily set to the time when reproduction is desired. Next, the video data is expanded from the condition of being compressed in the expansion processing part 3205 and the digital video data is converted to an analog video signal in a DA conversion part (referred to as DAC in the figure) 3207 and, then, is outputted to the switching part 3208.
In addition, in the switching part 3208, switching is carried out to select either the case where the input video signal, such as the current TV broadcast, is displayed in real time or the case where the video signal reproduced via the recording unit 3204 is displayed and, then, the corresponding video signal is outputted to the display part 3209 so as to be displayed.
In addition, in an apparatus which uses a recording medium, such as a magnetic disk or an magnetic optical disk, allowing random access which is an example of the time shift reproduction means 3200, specific reproductions such as a pause in reproduction, a forward direction high speed reproduction, a forward direction slow reproduction and a backward direction high speed reproduction can be easily implemented.
In the case that a means of reproducing video sound data recorded in such a recording medium, that is to say, the time shift reproduction means 3200 is constantly utilized for reproducing a video sound signal, it is possible to smoothly switch the reproduction conditions at the time when the reproduction conditions are switched from a normal reproduction to the above specific reproductions or at the time when the reproduction conditions are switched from the above specific reproductions to a normal reproduction.
However, since a time lag due to signal processing time on the time shift reproduction means 3200 side occurs between the inputted video sound signal, primarily transmitted in real time, and the video sound signal outputted from the time shift reproduction means 3200 which reproduces data that has once been recorded in a recording medium, in some cases the smooth switching of reproduction conditions becomes difficult at the time of constant utilization of the time shift reproduction means 3200.
For example, in the case that the input video sound signal is a TV broadcast, when a viewed channel (of a TV station) is switched and switching is carried out from the input video sound signal transmitted in real time to the video sound signal outputted from the time shift means 3200, time for processing the signal of the channel switched to is required before the video sound signal is outputted from the time shift means 3200. This processing time becomes the amount of time of the above time lag during which a blank screen is displayed on the display part 3209 and, as a result, a smooth switching of the input video sound signal is not carried out.
The switching part 3208 corresponds to the above described condition and takes into account, in advance, the reproduction conditions in the two means of the time shift reproduction means 3200 and the means of reproducing an input video sound signal in real time so that signals from both means are switched by receiving a signal input from the means of real time reproduction according to timing which causes a time lag.
However, in the case that switching from a normal reproduction to a specific reproduction is carried out, that is to say, in the case that the condition of reproducing an input video sound signal in real time is shifted to the condition of a backward direction high speed reproduction or a forward direction low speed reproduction, or in the case that switching is carried out from the forward direction high speed reproduction from a recording medium to a real time reproduction of an input video sound signal, the effect of the above described time lag cannot be removed even by means of the above described method and a smooth switching of the reproduction conditions cannot be realized.
In addition, though only in the case that input video sound data is constantly reproduced in real time without being recorded in a recording medium and specific reproductions such as a pause in reproduction, a forward direction high speed reproduction, a forward direction slow reproduction, a backward direction high speed reproduction are carried out, a smooth output of the switched input video sound data is possible when the video sound data recorded in the recording medium is reproduced, a time lag has occurred between the input video sound data and the video sound data outputted via the recording medium as is already described and, therefore, a time lag has occurred between the video sound data at the time of normal reproduction and the video sound data at the time of specific reproduction when the reproduction condition is switched from the normal reproduction to the above or when the reproduction condition is switched from the above specific reproduction to the normal reproduction and, thereby, a smooth switching of the reproduction conditions can not be realized because of effects of this time lag.